The present invention relates to an image recording apparatus, and more particularly to a type thereof in which an exposure condition is controllable in accordance with characteristic of a photosensitive recording medium applied.
One conventional image recording apparatus is shown in FIG. 1. However, it should be noted that the apparatus shown in FIG. 1 is also available in the present invention.
The recording apparatus 1 pertains to a full color copying machine and employs a photosensitive sheet medium including a microcapsule sheet and a developer sheet those described in U.S. Pat. No. 4,399,209. At an upper portion of the apparatus 1, a transparent original support glass 2 for mounting an original 4 thereon and a cover 3 for selectively covering the support glass 2 are laterally movably provided. On the original support glass 2, the original 4 is mounted with its imaging surface facing downwardly. At a position below the original support glass 2, there is provided a light source 5 including a halogen lamp 5a and reflection members 5b and 5c for irradiating a line-light to the original 2 through the original support glass 2 by way of a slit formed in a pivotable upper wall 1b of a frame body 1a. The line-light passes through the original support glass 2 and is reflected at a surface of the original 4. The halogen lamp 5a extends in a direction perpendicular to the moving direction of the original support glass 2. During light emission from the light source 5, the original support glass 2 is laterally moved so that the overall area of the original 4 is subjected to light irradiation line by line basis.
At a central portion of the copying machine 1, an exposure stand 10 is disposed. Further, between the light source 5 and the exposure stand 10, there is provided an optical system including a color tone controlling filter unit 8, a light condensing lens unit 7 and a pair of reflection mirrors 9a and 9b. The color tone controlling filter unit 8 and the lens unit 7 are attached to an attachment piece 34, whereas the pair of reflection mirrors 9a, 9b are secured to an attachment plate 9c which is movable for controlling optical path length and focal length relative to a photosensitive recording medium such as a microcapsule sheet 11 on the exposure stand 10. Therefore, light from the light source 5a passing through the slit is reflected at the original 4, and the reflected light passes through the filter unit 8, the lens unit 7 and the reflection mirrors 9a, 9b, to thereby reach the exposure stand 10. In other words, generally J-shape light path is provided between the light source 5 and the exposure stand 10 so that the light direction can be substantially inverted. Consequently, at the exposure stand 10, a latent image is formed on the microcapsule sheet 11 corresponding to an image of the original 4. More specifically, light exposed microcapsules are photo-cured, whereas unexposed microcapsules are not hardened. Incidentally, a light shielding cover member 1c is provided for preventing the light from the original from applying on the microcapsule sheet 11 running at a position in the vicinity of the optical unit. In other words, the light can only be passed through a slit 1d of the shielding wall 1c for permitting light exposure to the sheet 11 at the exposure stand 10.
At an upper inner space of the copying machine 1, a microcapsule sheet cartridge 12 is detachably provided, and a tape-up shaft 15 is rotatably provided. In the sheet cartridge 12, stored is the rolled microcapsule sheet 11 carrying microcapsules which encapsulate therein chromogenic material for color copying. A cartridge shaft 12a is provided for winding the microcapsule sheet 11 thereover. A plurality of feed rollers 14a, 14b are rotatably provided so as to feed the elongated microcapsule sheet 11 from the sheet cartridge 12. The thus pulled-out microcapsule sheet 11 passes through the exposure stand 10 where the sheet 11 is exposed to light in order to form a latent image thereon. The sheet 11 is taken up over the take-up shaft 15.
Below the exposure stand 10, a developer sheet cassette 17 is detachably provided which stores a stack of cut developer sheets 16. Further, a sheet feed mechanism 18 such as a suction foot is provided for feeding each one of the developer sheet 16. For the sheet further delivery, a feed roller 19a and a pinch roller 19b and a guide plate 19f are provided. At a downstream side of these rollers 19a and 19b, a developer sheet rollers 19c, 19d and a resist gate 19e are provided so as to align a leading edge of the developer sheet 16 in order to feed the developer sheet 16 to a pressure developing unit 13 with its correct orientation. Incidentally, instead of the suction foot 18, a drive sector roller (not shown) is also available.
Further, the pressure developing unit 13 having a small diameter roller 13a and a back-up roller 13b is provided between the exposure stand 10 and the tape-up shaft 15. The light exposed portion of the microcapsule sheet 11 and the developer sheet 16 delivered from the cassette 17 are in close contact with each other and these are pressed together by the rollers 13a, 13b. Consequently, non-exposed microcapsules are ruptured by the pressure for causing chromogenic reaction between a chromogenic material in the microcapsules and the developer materials on the developer sheet 16, and as a result, a colored visible image corresponding to the latent image is formed on the developer sheet 16.
Further, at a downstream side of the pressure developing unit 13, two sheet passages are provided for directing the microcapsule sheet 11 toward the take-up shaft 15 and for directing the developer sheet 16 to a thermal fixing unit 20. For this, a pair of feed rollers 14c are provided at exit side of the pressure developing unit 13, and a separation roller 14d is provided at a downstream side of the feed rollers 14c for separating the microcapsule sheet 11 from the developer sheet 16. A meandering travel control roller 14e is movably provided between the separation roller 14e and the take-up shaft 15. Furthermore, at downstream side of the separation roller 14d, the sheet heating device 20 is provided for thermally fixing an output image on the developer sheet 16. At downstream side of the sheet heating device 20, a sheet tray 21 is provided for receiving the developer sheet carrying the final output image.
Upon manipulation of a start button (not shown), the original support glass 2 is moved to one direction (rightwardly in FIG. 1), so that a left edge of the original is brought into confrontation with the halogen lamp 5a, and thereafter, the halogen lamp 5a is turned on. The original support glass 2 is then moved to opposite direction (leftwardly in FIG. 1) during which the original 4 is successively subjected to a line-light exposure.
At the same time, the microcapsule sheet 11 is moved toward the take-up shaft 15 at the speed equal to the moving speed of the original support glass 2. Therefore, a latent image corresponding to the original image is successively formed on the microcapsule sheet 11 when it travels over the exposure stand 10. On the other hand, each one of the developer sheet 16 is delivered from the sheet cassette 17 to the pressure developing unit 13 in synchronism with the every leftward movement of the original support glass 2. The latent image portion of the microcapsule sheet 11 and the developer sheet 16 are pressed together at the pressure developing unit 13, so that a colored visible image is formed on the developer sheet 16. Thereafter, the developer sheet 16 is introduced into the sheet heating device or the thermal fixing unit 20 by means of the feed rollers 14c so as to fix the color image on the sheet 16, and is then discharged onto the discharge tray 21. On the other hand, the microcapsule sheet 11 passes through the separation roller 14d, and the meandering travel controlling roller 14e and is wound over the take-up shaft 15.